排焰道流动损失对地下井引射性能的影响

Effects of Exhaust Channel Flow Loss on Underground Silo Ejection Performance

关键词:  地下井  排焰道  引射器函数  静压协调函数  驻点极限  阻力系数

Key words:  Underground silo  Exhaust channel  Ejector function  Static pressure matching function  Stagnation critical point  Resistance coefficient

摘要:

针对地下井引射器设计问题，基于引射器函数理论和可压缩流体管道流动理论，提出了一种考虑排焰道流动损失的地下井引射器描述方法，并结合理想引射器数学模型，分别建立了考虑排焰道流动损失的基本引射器数学模型和极限引射器数学模型。基于这两个数学模型，引入考虑排焰道流动损失的引射器函数和静压协调函数，分析了发动机总压、混合室直径、总体冲量阻力系数对地下井引射性能的影响和总体冲量阻力系数随排焰道阻力系数和转角的变化规律。结果表明，不能通过持续增大发动机总压和减小混合室直径的方法获得较低的混合室入口压强，较小的总体冲量阻力系数可以获得较低的混合室压强，总体冲量阻力系数随着转角的减小和阻力系数的增大而增大。

Abstract:

Aiming at the design of underground silo ejectors， a description method of silo ejectors considering exhaust channel flow loss was proposed， which based on the theory of ejector function and compressible fluid dynamics in pipe. Combined with the ideal ejector mathematical model， the basic ejector mathematical model considering the flow loss of the exhaust channel and the limit ejector mathematical model were established respectively. Based on the two mathematical models， introducing the ejector function and the static pressure matching function considering the exhaust channel flow loss， effects of total engine pressure， mixing chamber diameter and total impulse resistance coefficient on the underground silo injection performance were studied. And the variation law of total impulse resistance coefficient along with the exhaust channel loss coefficient and turning angle was analyzed. Three conclusions can be obtained from the simulation results. Higher engine total pressure and lower diameter of the mixing chamber cannot acquire lower inlet pressure of the mixture chamber. Lower total impulse resistance coefficient can acquire lower inlet pressure of the mixture chamber. The total impulse resistance coefficient increases when the exhaust channel loss coefficient increases and the exhaust channel turning angle decreases.